Pathological studies of cheek teeth apical infections in the horse: 1. Normal endodontic anatomy and dentinal structure of equine cheek teeth.

This study examines the normal endodontic anatomy and dentinal structure of equine (horse) cheek teeth. This study used four methods—gross examination, dissection microscopy, computerized axial tomography, and decalcified and undecalcified histology on 100 normal equine cheek teeth. It offers new insights into their dentinal structure and proposes a shift in the terminology related to the types of dentine.

Plain Overview

Researchers conducted in-depth anatomical and structural studies on the cheek teeth of horses. Using microscopic dissection, tomography, and undecalcified histology, the study identifies the number of pulp horns in various positions and describes the characteristics of primary, secondary, and tertiary dentine. A proposition was made to reclassify a type of dentine currently termed as tertiary dentine.

Methods

• Investigation was based on morphological examinations on 100 normal horse cheek teeth, with dental age ranging from 1-12 years (since eruption).
• Four methodologies were used: gross examination, dissection microscopy, computerised axial tomography, and decalcified and undecalcified histology.

Findings

• In the positions denoted as Triadan 07-10, five pulp horns were consistently found, whereas the 06 CT had an extra pulp horn located more rostrally (towards the front).
• The mandibular (lower jaw) Triadan 11s had six pulp horns, while the maxillary (upper jaw) Triadan 11s had seven.
• When sections of the cheek teeth were taken 2-6mm below the occlusal surface (the area where teeth meet when the jaws bite), pulp presence was observed. About 50% of individual maxillary cheek teeth pulp horns and 25% of individual mandibular cheek teeth pulp horns contained pulp.

Dentine Description

• The study also highlights the histological appearances of different types of dentine: primary, secondary, and tertiary.
• The research proposes a classification change, suggesting the type of dentine present most centrally in each pulp chamber, currently called tertiary dentine, be reclassified as irregular secondary dentine.
• It is proposed that “tertiary dentine” be reserved only for the dentine areas laid down following the damage to dentine or pulp.